個人比較推薦使用BastiaanJansen/otp-java，使用簡單，而且包含了生成以及校驗

參考程式碼

pom.xml

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0"

         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 

    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>

    <artifactId>lakefs-app</artifactId>

    <version>1.0-SNAPSHOT</version>

    <properties>

        <maven.compiler.source>8</maven.compiler.source>

        <maven.compiler.target>8</maven.compiler.target>
 

    </properties>

    <dependencies>

        <dependency>

            <groupId>com.github.bastiaanjansen</groupId>

            <artifactId>otp-java</artifactId>

            <version>1.3.0</version>

        </dependency>

        <dependency>
 

            <groupId>commons-codec</groupId>

            <artifactId>commons-codec</artifactId>

            <version>1.15</version>

        </dependency>

    </dependencies>

</project>

程式碼

package com.dalong;

import com.bastiaanjansen.otp.HMACAlgorithm;

import com.bastiaanjansen.otp.TOTP;

import java.security.InvalidKeyException;

import java.security.NoSuchAlgorithmException;

import java.time.Duration;

public class App {

    static final  String myKey = "dddddd";

    public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeyException {

        TOTP.Builder builder = new TOTP.Builder(myKey.getBytes());

        builder

                .withPasswordLength(6)

                .withAlgorithm(HMACAlgorithm.SHA1) // SHA256 and SHA512 are also supported

                .withPeriod(Duration.ofSeconds(30));

        TOTP totp = builder.build();

        String mycode =  totp.now();

        System.out.println(mycode);

    }

}

說明

otp 做為系統雙因素認證是一個簡單方便的東西，我們可以方便的基於開源的otp包開發自己的otp整合方案
可能在使用中會有Caused by: java.lang.ClassNotFoundException: org.apache.commons.codec.binary.Base32 的問題
以為bastiaanjansen的otp 依賴了commons.codec，因為專案依賴衝突了，解決方法很簡單，就是新增依賴（參考上邊的）

參考資料

https://github.com/BastiaanJansen/otp-java
https://github.com/jchambers/java-otp
https://github.com/amdelamar/jotp